End Chapter 2, Mishna 4
A Shabbos lunch incident at the Exilarch’s house: on Friday, he asked Rav Huna bar Chinana to arrange for Shabbos-carrying between a pavilion in a non-residential enclosure and the house via a path lined by reeds on two sides. Rava thought this arrangement erroneous, tore down the reeds, and his students removed the reeds so they wouldn’t be restored. On Shabbos, Rava and his students realized they were wrong for multiple reasons, but it was too late to do anything about it, and the beautiful lunch in the pavilion was cancelled. Rabbi Elai taught in the name of Rabbi Eliezer that a karpef can be much bigger than 2 beis seah, and sourced it in a verse from II Kings 20:4. From that story about Isaiah and ill King Hezekiah, we learn that it’s good to learn in the merit of an ill person, but not right outside their door lest we provoke the prosecuting angel, Satan. Rabbi Elai also taught in the name of Rabbi Eliezer concerning a courtyard eruv that one resident forgot to join before Shabbos.